Engraving bit with spring housing

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Engraving bit with spring housing

Postby SpyderHelix » Sat Jun 15, 2013 2:46 am

Just wanted to share how I made a spring diamond engraving bit, I know you can find the instructions all over the net, but what the heck - if I can give someone a good idea then I'm contributing back. :)
First off - I bought a 1/8 diamond engraving bit from J&M Diamond tool online..it came about a week later, it was 5 inches long. Total with shipping was $21.
(To make a similar holder to mine, you will need access to a lathe)
After using the edge of a grinding wheel to 'cut' the engraver down to size (I cut mine to 2" long) I grabbed some aluminum stock we had at work and turned it down to .250 OD..center drilled it and then drilled it through with a .120" drill. Since it was to house a 1/8 inch engraver, I used a reamer to ream the drilled hole to a true .125" then cut the sleeve down to .700 in length, which is the length of the ER11 collets I have.
Image


Being an impatient sort, I could have looked for, and bought a .125 set screw collar..but why when I can make one?
So I grabbed a piece of mild steel round, turned it down to .375 diameter and drilled it with a 1/8" drill..then used a grinding wheel to spot a flat on it for drilling. I chose to use a 6-32 set screw, and drilled and tapped the collar for that.
To secure the end of the assembly, I wanted to make sure it didn't pop out but I wanted to make sure I could tweak it if I needed to later on (a new housing or whatever) so I drilled and cut a piece of round plastic for the end, turning it smaller then the outside of my sleeve so it didn't bind inside as the needle moved.
to secure it I used 5 minute epoxy - strong enough to hold it in place, but pretty easy to remove with a knife in case it needed adjustment.
Image


For a spring, I went to a local big box store (Diamond home improvement) and picked up a spring that suited my needs and then cut it to size (as it was too long)
Fully assembled:
Image


And one of the clock faces I am making from hard drive platters:
Image


There is NO burring whatsoever, and the parts come off as clean as can be.
Not bad for a starter engraver.

Also wanted to add that my boss wanted to give the engraver a try for production parts we engraved for a customer -
Image


I ran 50 of these parts in a 4th axis on my machine at work (Haas VF0 VMC) - parts were plated with optical black anodizing, then run over with the engraving tool pictures above..the result pictured was after 2 passes with .020 pressure.
The amount of wear on the cutter was incredibly minimal, even after running through the anodizing - It just shined the cutting surface for me :)
There was some minute chipping going on, but we figure it's from the width of the engraving cutter.
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Re: Engraving bit with spring housing

Postby jblakey » Tue Jul 02, 2013 1:29 pm

very sweet!

is that aluminum tool you engraved? Or steel?

Any chance that you might make up another one of these engravers? (hint, hint)? I've got a few projects I wouldn't mind trying, but I don't have a lathe...

Thanks,
jason
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Re: Engraving bit with spring housing

Postby SpyderHelix » Mon Jul 08, 2013 10:10 pm

Both the platters and the black parts are aluminum.
I've upgraded the way I made the engraver, I'll post pictures later on when I can get my camera working.
Still uses the same engraving tool, but incorporates all the parts into one sleeve with a tension adjuster in the base.
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Re: Engraving bit with spring housing

Postby jblakey » Tue Jul 09, 2013 10:09 am

sweet! Anxious to see it


Thanks,
jason
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Re: Engraving bit with spring housing

Postby SpyderHelix » Thu Jul 11, 2013 12:55 am

So a coworker and I got together to see if there was a way I could improve my design on the engraver, and make it a little more friendly to my spindle without having a ton of stuff sticking out of the end..and as he was setting up a machine, he had a brainstorm and brought me his tap guide for an idea example - and it was brilliant!
So I ran over to the lathe and made a new housing for my engraving tip - shortened the rear of the shank on the engraver itself, moved the delrin ring closer to the front so it would clear the end of the holder and still capture the end of the spring to hold it in place, then ground down an 10-32 set screw to give headspace between the tip of the engraver and the end of the set screw.
The spring is simply a spring from a ball point pen, very lightly stretched to give it a little oomph.
Pro: it fits alot better in the spindle now, with more room to adjust. Also, less wiggle out of the engraving tip as it moves across the material.
Con: in order to adjust spring tension, you have to remove it from the spindle to crank the set screw in tighter, then put it back in.

Individual parts:
Image

Parts ready to be assembled:
Image

Assembly put together:
Image

Overall length of the engraving tool is 1.635" long.
Last edited by SpyderHelix on Thu Jul 11, 2013 2:43 pm, edited 1 time in total.
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Re: Engraving bit with spring housing

Postby johntech » Thu Jul 11, 2013 4:05 am

Spyder That is awesome!! That brings up some great ideas of designing a spring-loaded tool for cutting PC boards or maybe even a vinyl cutter .......hhmmmmmm!

John
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Re: Engraving bit with spring housing

Postby jblakey » Thu Jul 11, 2013 7:53 am

clean design and work! I was looking at those tap guides as a base, but I don't have a lathe, and the 1/2" diameter is impossible on my ER-11, and replacing the 3/16" bit that goes inside - diamond drags don't come in 3/16" (or are pretty rare, at least).



any chance of getting a version turned down to 1/4" external diameter instead of the 3/8"?

Thanks,
jason
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Re: Engraving bit with spring housing

Postby SpyderHelix » Thu Jul 11, 2013 12:06 pm

Oh, this design is 1/4" diameter :) I suppose I left that out - I have the same kind of collets - er11's, the biggest diameter I can hold is 1/4" bits.
J&M (the place I bought the diamond drag) only sells engravers in 1/8 or 1/4 diameters..(well, 11/64 too but what an odd size lol) so the only thing I could work with was the 1/8" tooling
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Re: Engraving bit with spring housing

Postby jblakey » Thu Jul 11, 2013 7:31 pm

Cool! Very excited!


Thanks,
jason
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